Proof of Theorem csbiebt
| Step | Hyp | Ref
| Expression |
| 1 | | elex 3501 |
. 2
⊢ (𝐴 ∈ 𝑉 → 𝐴 ∈ V) |
| 2 | | spsbc 3801 |
. . . . 5
⊢ (𝐴 ∈ V → (∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶) → [𝐴 / 𝑥](𝑥 = 𝐴 → 𝐵 = 𝐶))) |
| 3 | 2 | adantr 480 |
. . . 4
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → (∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶) → [𝐴 / 𝑥](𝑥 = 𝐴 → 𝐵 = 𝐶))) |
| 4 | | simpl 482 |
. . . . 5
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → 𝐴 ∈ V) |
| 5 | | biimt 360 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (𝐵 = 𝐶 ↔ (𝑥 = 𝐴 → 𝐵 = 𝐶))) |
| 6 | | csbeq1a 3913 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → 𝐵 = ⦋𝐴 / 𝑥⦌𝐵) |
| 7 | 6 | eqeq1d 2739 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (𝐵 = 𝐶 ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 8 | 5, 7 | bitr3d 281 |
. . . . . 6
⊢ (𝑥 = 𝐴 → ((𝑥 = 𝐴 → 𝐵 = 𝐶) ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 9 | 8 | adantl 481 |
. . . . 5
⊢ (((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) ∧ 𝑥 = 𝐴) → ((𝑥 = 𝐴 → 𝐵 = 𝐶) ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 10 | | nfv 1914 |
. . . . . 6
⊢
Ⅎ𝑥 𝐴 ∈ V |
| 11 | | nfnfc1 2908 |
. . . . . 6
⊢
Ⅎ𝑥Ⅎ𝑥𝐶 |
| 12 | 10, 11 | nfan 1899 |
. . . . 5
⊢
Ⅎ𝑥(𝐴 ∈ V ∧
Ⅎ𝑥𝐶) |
| 13 | | nfcsb1v 3923 |
. . . . . . 7
⊢
Ⅎ𝑥⦋𝐴 / 𝑥⦌𝐵 |
| 14 | 13 | a1i 11 |
. . . . . 6
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → Ⅎ𝑥⦋𝐴 / 𝑥⦌𝐵) |
| 15 | | simpr 484 |
. . . . . 6
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → Ⅎ𝑥𝐶) |
| 16 | 14, 15 | nfeqd 2916 |
. . . . 5
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → Ⅎ𝑥⦋𝐴 / 𝑥⦌𝐵 = 𝐶) |
| 17 | 4, 9, 12, 16 | sbciedf 3831 |
. . . 4
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → ([𝐴 / 𝑥](𝑥 = 𝐴 → 𝐵 = 𝐶) ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 18 | 3, 17 | sylibd 239 |
. . 3
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → (∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶) → ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 19 | 13 | a1i 11 |
. . . . . . . 8
⊢
(Ⅎ𝑥𝐶 → Ⅎ𝑥⦋𝐴 / 𝑥⦌𝐵) |
| 20 | | id 22 |
. . . . . . . 8
⊢
(Ⅎ𝑥𝐶 → Ⅎ𝑥𝐶) |
| 21 | 19, 20 | nfeqd 2916 |
. . . . . . 7
⊢
(Ⅎ𝑥𝐶 → Ⅎ𝑥⦋𝐴 / 𝑥⦌𝐵 = 𝐶) |
| 22 | 11, 21 | nfan1 2200 |
. . . . . 6
⊢
Ⅎ𝑥(Ⅎ𝑥𝐶 ∧ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶) |
| 23 | 7 | biimprcd 250 |
. . . . . . 7
⊢
(⦋𝐴 /
𝑥⦌𝐵 = 𝐶 → (𝑥 = 𝐴 → 𝐵 = 𝐶)) |
| 24 | 23 | adantl 481 |
. . . . . 6
⊢
((Ⅎ𝑥𝐶 ∧ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶) → (𝑥 = 𝐴 → 𝐵 = 𝐶)) |
| 25 | 22, 24 | alrimi 2213 |
. . . . 5
⊢
((Ⅎ𝑥𝐶 ∧ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶) → ∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶)) |
| 26 | 25 | ex 412 |
. . . 4
⊢
(Ⅎ𝑥𝐶 → (⦋𝐴 / 𝑥⦌𝐵 = 𝐶 → ∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶))) |
| 27 | 26 | adantl 481 |
. . 3
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → (⦋𝐴 / 𝑥⦌𝐵 = 𝐶 → ∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶))) |
| 28 | 18, 27 | impbid 212 |
. 2
⊢ ((𝐴 ∈ V ∧
Ⅎ𝑥𝐶) → (∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶) ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |
| 29 | 1, 28 | sylan 580 |
1
⊢ ((𝐴 ∈ 𝑉 ∧ Ⅎ𝑥𝐶) → (∀𝑥(𝑥 = 𝐴 → 𝐵 = 𝐶) ↔ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶)) |